Cheap Milk for Sale

I saw an ad for a local grocery store that advertised 4 half gallons of milk for $1.00 each. But you had to buy 4 of them to receive that price. And the regular price was not given. We don't use one half gallon of milk in a week, so would never be able to use 4 half gallons before they spoiled. And while I am talking about ads for groceries, from my experience with teaching fourth graders, I would assume that many people are not able to figure out the best buy in groceries. Stores make it so confusing and often complicated to figure some of the prices. Too bad we don't have a uniform way of listing sales prices.